Valve.



w. M. FULTON.

VALVE.

APPLICATION FILED JULY 9, 1906.

Patented Dec. 29, 1908.

I affoznmjj UNITED STATES PATENTV OEEIOE.

WESTONM. FULTON, OE KNOXVILLE, TENNESSEE, -AssIeNoR To THE FULTONKNOXviLLE, TENNESSEE, A CORPORATION OE MAINE.

COMPANY, or

VALVE.

regulators, and has for its principal objects to secure great delicacyand uniformity of operation of the valve combined with durability in itsconstruction; to eliminate in great-measure the friction due to movementof the valve stem; to secure stability and steadiness in operation ofthe valve -while subject to ydisturbances due to vorticular flow ofluidpast the valve, and in short to y provide a balanced valve whichwill offer a minimum and uniform resistance to the valve-controllingdevice.-

Balanced valves as heretofore constructed lack delicacy in action andoffer comparatively large and varied resistances to movement whenoperated by automatic regulators such as thermosensitive or pressuresensitive devices, thereby preventing the latter devices from properlymaintaining the'temperature or pressure for which such devices are set.It is therefore essential that the heat or pressure sensitive regulatorshould Work against a uniform resistance in the valve, a condition whichis not attained to a sufficient degree in the forms of valves nowgenerally in use with such regulating devices.

'f he valve stem working through its packing box oiiers a variedresistance to the sensitive regulator due in part to mechanical wear, tochanges in temperature and deterioration of the packing material- Thisresults in an unstable operation of the valve, enabling the automat1cregulator to open and close it Awith `ease at one time vand withdiiiiculty at anv other, thereby destroying-the uniformity ofregulation, one ofthe main objects sought. Fluctuations in .the powernecessary to lbe supplied by the regulator to move the valve stem alsoresult from the vorticular movement of the iiuid passing through thevalve opening and about the valve cap, either to assist `or retard themovement of the valve stem. A further cause in the irre ular resistanceoffered to thev movement, the valve stem results from variations ofpressure of the A fluid controlled by the valve even incasevSpecification of Letters Yatent. "Applicaties med my 9, isos. sean No.saam.

.mereiv vlllfA lnaaid drawings-Figure 1 isa vertical 4 Patented nec.-2o, ioos of so-called balanced valves when the uid pressure on the valvecaps is supposed to he alanced. One of the reasons for this lies in thefact that the valve is not balanced in all positions of the valve ca s,and that no proper provision is made or balancing the varying pressureon the end of the valve stem, which would detract from the accurac ofthe automatic control. Valves Whi oi'er such varied resistance will bevery unstable in operation when controlled by a delicate regulator, andwill be subject to sudden opening and closing motions with every changein fluid pressure in the valve casing, thereby detracting from theaccuracy of automatic control and resulting in unnecessary wearing ofall working. parts and limiting the life both of the valve and the rlator. i

eretofore in valves of the class referred to, it has been sou ht tobalance the Eressure on the end of t e valve stem by in than itscompanion. While this arrangement provides for accurate balancing whenthe valve caps are seated, the balance or uilibriumis not, however,maintained W en the caps are raised from their seating position. Owingto vorticular disturbances Set up by the fluid passing the valve caps,which disturbances are not roportional to the areas of the valve capsbut to their ciroumferences, vorticular action on the valve caps isconsequently greater on one cap than the other, causing unstableoperation of the valve and interfering with the delicate operation ofthe automatic regulater. To overcome objections of the character abovenoted, and to attain the objects of this invention, l provide means forbalancing iluid pressures on the valve caps and valve stem due both tostatic pressure and that resulting from the movement of the iluid or toits kinetic energy wherebythe valve stem will offer va substantiallyuniform resistance to movement in all working positions.

Certain mechanical expressions of the inventive idea involved are showninthe accompayiililg drawings, which are designed as ustrations toassist in the de scrioln of the inventionl and not as defining 'tsthereon W 6 in which are located in line with each ot er two valve seats7 and 8. The valve casing 1 is also provided with exteriorly threadedtubular shoulders 9, 10, the .openings being opposite the valve seats 7,8. Engaging the threaded shoulders 9 and 10 are two caps 11 and 12 ofidentical construction, each having a ledge 13 which in association withshoulder 9, of the valve casing, receives and retains the annular flangeplate 14 sealed to the inner end of the flexible wall 15, the oppositeend of which is sealed to an inner pro'ecting iiange plate 16, restingagainst a shou der 17 onthe valve stem 18 and held firmly against thesame by clamping nuts 19 and 20. Nut 19 is preferably. provided with asocket for receiving a head 21 on the arm 22 which connects with asensitive regulator not shown, and sensitive to heat or pressure, theoperation of which imparts movement to the valve stem. Fast to the valvestem 18 are two valve caps 23, 24 provided with the usual guideflanges25.. 'lhe conical valve seats7, 8 are of the same diameter andmade on the same bevel and their bearing sur- 'faces are reduced to anarrow band for receiving the cone-shaped valve caps 23, 24 byunder-cutting the valve seats at points 26, 27. 'l'he surface contact ofthe valve caps 23, 24 and their valve seats 7 and 8 is thereby reducedto a narrow ledge, yet quite sufficient to ive an accurate fit and makea fluid-tight c osu're. While retaining the conical seats, equilibriumof static pressures on the valve Vcaps is practically secured, anddisturbances from vorticular movement of the fiuid passing around thelifted valve cap are also balanced.

The o eration of the device as thus far describe is as followsz-Afterassembling the larts of the valve, assume that they are in t e positionshown in Fig. 1, with the valve caps 2 3 `and 24 seated, and the valvestem 22 coupled to an automatic heat or ressure-controlled regulator,not shown. luid under high pressure enters the space 4 and exerts equaland o osite pressures on valve caps 23 and 24 w ich expose substantiallyequal areas to the incoming fluid. The

valve stem has therefore no tendency to.

move due to inco fluid pressure.` The fluld pressure on the aces ofthevalve caps exposed to :pressure in. space 5- are `lralso p in gequilibrium for a like reason, and the pressures on the interior4 of theflexible walls connected to the valve stem 'are mutually opposed to eachother, and being equal because of the equal surfaces of the wallsexposed to fluid pressure in valve space 5, likewise have no tendency tomove vthe valve stem. It is particularly to be noted that the ends ofthe valve stem are not exposed to the iiuid pressure on either side ofthe valve csps, but are open to atmospheric pressure o and therefore arenot subject to4 that unstable operation arising when the two ends of thevalve stem are subject to different and varying pressures. Vvhen thevalve stem and with it the valve caps are lifted from their seats by theoperation of the regulator, the equilibrium of pressures above referredto is ing fluid on the faces of the valve caps remains constant, thevorticular disturbances y due to movement of the fluid past each valveare neutralized because thetwo caps a;e of equal circumference, thepressure on the corrugated walls and the end closures remain equal andopposite and the ends of the valve stem are not acted on by the fluid inquestion. The valve offers uniform resistance to movement by thecontrolling device which operates within the valve or by vorticulardisturbances producedby the fluid in passing through the valve whateverbe the nature of the fluid.

While prefer to give to my invention the mechanica expression abovedescribed, yet it may be embodied in other forms without de arting fromthe s irit thereof. Whereas in lFig. 1 the collapsi le walls 15, 15 areprovided with outer end closures of4 equal area pipes for heatingpurposes, Where convectional action is the force which propels thecirculation, and hence any obstruction thrown across the path 4of thecirculating water is sufficient to sto the circulation even though theclosure t us formed is not altogether water-tight. The valve consists ofa hollow shell 29, having threaded openings 30, 31, in the opposite endsthereof, and threaded side openings 32, 33, `which latter openings areclosed by the flexible corrugated walls 34, 35, which have the rigid endwalls 36, 37 therein, and which are connected to the main body of thevalve by caps 38, 39, inthe manner alread described in Fig 1. Asemi-circular ann ar ledge extends through its middle half way aroundthe interior of shell 29,l and surface, said axis 43 aving bearings inthe opposite sides of shell 29, so that, when in the position shown inFig. 2, said gate is in Acontact with ledges 40,` 41 around itsperiphery and thus obstructs the ow of fluid through the valve. An aim44 attached to gate 42, has pivoted to its outer extremity 45 the rod 46which extendsdownward from end Wall 37. A stud 47 preferably integralwith shell 29, extends upward and has'arectangular slot 48 in its upperextremity, through which slot passes the balance lever 49 fulcrumed on aknife-edge 5() which closes the upper end of slot 48. End wall 36 has anupward extension 51 provided with a knife-edge bearing against the endof lever 49. The extension 45 from end wall 37 has a slot 52 therein toreceive one end of lever 49 and the lower end of slot 52 is closed by aknife-edge bearing for said lever.v 'lhe automatic regulator may beconnected y to the valve at 53, as described above in relation toFig. 1. As already stated, wall 36 may be of greater diameter than Wall37,and the position of stud 47 may be such that the end Vof lever 49,against which projection 51 bears, is just sufficiently shorter than theend against which projection 45 bears to compensate for the differencein pressure exerted on the opposite ends of lever 49 due to the unequalsurface areas of end walls 36, 37. Since rod 46 forms a portion of endwall 37, the fluid pressure against the lower end of said rod is to becounted as a part of the pressure against end wall 37 Since it ispractically impossible to make a valve of this type liquid-tight, thefluid pressure is always the same on both sides of gate 42, whether thevalve be open or closed.

'lhe operation of the valve Will be readily understood from what haspreceded. 'lhe valve by means of the flexible walls and lever oflers auniform resistance to the automatic regulator in all positions of thevalve gate. In this construction of valve the pressure on unit surfaceis practically the same onv opposite sides the valve-gate, andvariations of pressure within the casing do not disturb the ortionparallel to its a equilibrium established between the two flexiblewalls. Vorticular disturbances are absent in a valve of this characterbecause the convectional circulation. of the water is feeble and thevalve is not intended to effect a fluid-tight closure.

What is claimed is:

1. In combination, a valve casing, op ositely disposed collapsible andex ansi le vessels opening into sald caslng an havlng end closures ofsubstantially equal area exposed on one side to fluid pressure withinthe casing and on the other side to atmospheric pressure, two valveseats having reduced bearing surfaces, valves for seatin thereon ofequal cross-sectional area and aving a connection With said endclosures.

2. In combination, a valve casing, op ositely disposed expansible andcollapsi le vessels opening into said casing, said walls having endclosures exposed on one side to equal and opposite fluid pressure withinthe casing and on the opposite side to atmospheric pressure, a valveprovided with a valve stem connected to said end closures the ends ofsaid valve stem being free from fluid pressure within the casing.

3. In a valve of the character described, the combination of a valvecasing, collapsible and expansible vessels having flexible corrugatedmetal walls, means for connecting said vessels, each of which is exposedexteriorly to atmospheric pressure and interiorly to a fluid pressuretending to move said Walls in opposition to each other, and a valvewithin said casing movable with said walls.

4. In a valve of the character described, the combination of a valvecasing, a valve stem therein having inwardly and outwardly openingvalves thereon of e ual cross-sectional area and valve-seats t erefor,oppositely disposed collapsible and expansible vessels each having oneend stationary and the other end fast to said valve stem, the saidvessels being exposed exteriorly to equal fluid pressures and openinginterlorly into the valve casing for applying equal and o osite fluidpressures to the valve stem in a positions of the valves.

In testimony whereof I have signed this specification in the presence oftwo subscribing Witnesses.

WESTON M. FULTON.

Witnesses:

E. T. MANNING, ARTHUR SAVAGE.

